Tomorrow is again 519, do you remember that day in 2021? As someone who experienced it firsthand, that feeling is truly unforgettable. The black swan suddenly descended, and how many people were wiped out overnight? That thrill of huge swings, honestly, it's hard to experience again now.

The 519 event in the crypto world happened five years ago, but the details are still vivid. How fierce was the crash that day? Bitcoin plummeted from $43,000 straight down to $30,000, a 30% drop. Ethereum was even worse, crashing from $3,300 to $1,900, a 42% decline. Other coins were cut in half again and again, some even dropping over 50%. Exchanges were directly overwhelmed at the time; many people couldn’t close their positions and could only watch their assets shrink.

How did this storm come about? The most direct trigger was Elon Musk. He previously bought $1.5 billion worth of Bitcoin with Tesla and said they would accept Bitcoin payments, stirring up the market with tweets and Dogecoin hype, boosting the entire market. But on May 12, he suddenly did a 180-degree turn, announcing they would stop accepting Bitcoin payments, citing environmental concerns over mining energy consumption. This directly shattered market confidence, and Bitcoin dropped sharply.

But Musk was only the superficial cause. There were deeper issues behind it. The first four months of 2021 were a crazy bull market, with Bitcoin rising from $30,000 at the start of the year to $64,000 in April, more than doubling. Mainstream coins like Ethereum and Litecoin also surged several times, not to mention meme coins like Dogecoin and Shiba Inu, which soared thousands of times. These rises had no fundamental support; they were bubbles built on social media hype and speculative chasing. Bubbles always burst.

Adding to that, China’s three major associations issued notices banning virtual currency trading, and Inner Mongolia strengthened mining regulation. Once regulatory signals appeared, panic spread. Market sentiment flipped from greed to fear in an instant, and investors started frantic sell-offs, creating a vicious cycle.

The panic index during the 519 event soared to 0.8, and the greed index dropped to 10—extreme data. But it was precisely because of these extremes that a V-shaped reversal followed. By May 20, Bitcoin rebounded to $40,000, and Ethereum recovered to $2,800. The drops turned into buying opportunities.

Looking back now, 519 was indeed a watershed moment for the crypto market. Back then, the market was still largely driven by retail investors, with extreme emotional swings. Now, Bitcoin is heavily controlled by Wall Street, with institutional forces dominating the market rhythm. It’s indeed harder to see that kind of exhilarating scene. But history repeats itself; only the form changes. Every 519 in crypto reminds us that risks always exist, and rationality is always scarce.